package com.wufumall.dataexporter.config;
import java.io.IOException;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;

@Configuration
public class JacksonConfig {
  
  @Bean
  @Primary
  @ConditionalOnMissingBean(ObjectMapper.class)
  public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
      ObjectMapper objectMapper = builder.createXmlMapper(false).build();
      objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
          @Override
          public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
              jsonGenerator.writeString("");
          }
      });
      return objectMapper;
  }

}
